Sol-gel synthesis of Ln₂(Ln = La, Nd)Ti₂O₇

Abstract

Lanthanum and neodymium titanates were prepared by a sol-gel route. Synthesis of La 2 Ti 2 0 7 from pure alkoxide precursors yielded an intermediate perovskite type phase, La ( i-^)TiO 3 , which partially transformed to La 2 Ti 2 07 on heating to 1500 °C. Substitution of the lanthanum acetylacetonate for alkoxide precursor yielded La 2 Ti 2 0 7 without any intermediate phase at a very low temperature of 700 °C. Sintering of the La 2 Ti 2 0 7 gel powder yielded a highly dense ceramic with -97% theoretical density. Similar sintering treatment resulted in ~92% theoretical density for Nd 2 Ti 2 O 7 .

Microstructure and Nanoscale Piezoelectric/Ferroelectric Properties in La2Ti2O7 Thin Films Grown on (110)‐Oriented Doped Nb:SrTiO3 Substrates

“…[21] Various techniques have already been successfully employed for the deposition of LTO thin films, e.g., the spray pyrolysis technique, [22] the metal-organic deposition combined with spin-coating, [23,24] the pulsed laser ablation, [25,26] the polymeric complex method, [27] and various sol-gel techniques. [28][29][30] The aim of this paper is both to present a complete structural study of LTO thin films by high resolution X-ray diffraction (HR-XRD) and to investigate their piezoelectric/ ferroelectric properties at the local scale by piezoresponse force microscopy (PFM) and first-principles density functional computations. We demonstrate that only a meticulous analysis of the microstructure permits to clarify the ferroelectric properties measured at the nanoscale level in our LTO films.…”

Structural Characterization and Photoluminescent Properties of (La1–xSmx)2Ti2O7 Solid Solutions Synthesized by a Sol–Gel Route

“…[16,18] There are several synthesis routes for Ln 2 Ti 2 O 7 compounds (Ln = La and Sm) such as traditional solid-state reactions, [1,19,20] polymerized-complex methods, [21] hydrothermal synthesis, [22] coprecipitation methods, [13] metalorganic decomposition methods, [23] and sol-gel synthesis. [24][25][26] However, to the best of our knowledge, there is no report of the synthesis of a (La 1-x Sm x ) 2 Ti 2 O 7 solid solution.…”

Synthesis of Er2Ti2O7 nanocrystals and its electrochemical hydrogen storage behavior

“…In particular, many of these pyrochlore oxides undergo a hightemperature (1100-1400 • C) formation process and long-reaction time (1-2 d) [11,14], which is very energy and time consuming. So, attempts to synthesize nanoscale pyrochlore oxides under mild condition have been carried out by several soft-chemistry techniques, such as co-precipitation [15,16] and sol-gel methods [17,18]. In recent years, there have been some reports about how to fabricate pyrochlore oxides below 900 • C [19,20] consumed an organic reagent, such as ethylene glycol, ethanol, etc.…”